Response and Amplification of Terahertz Electromagnetic Waves in Intrinsic Josephson Junctions of Layered High-Tc Superconductor

TL;DR

This paper explores how stacks of intrinsic Josephson junctions in layered high-Tc superconductors can amplify terahertz electromagnetic waves through cavity resonance and phase kink excitation, with potential applications in THz detection.

Contribution

It demonstrates the amplification mechanism of THz waves in IJJs via cavity resonance and phase kinks, highlighting a new method for THz wave amplification and detection.

Findings

Significant amplification of THz waves occurs at cavity resonance frequencies.

Excitation of pi phase kinks stimulates cavity resonance and energy transfer.

IV characteristics show a current step indicating resonance and potential for wave detection.

Abstract

We investigate the response of a stack of intrinsic Josephson junctions (IJJs) to terahertz (THz) electromagnetic (EM) irradiation. A significant amplification of the EM wave can be achieved by the IJJs stack when the incident frequency equals to one of the cavity frequencies. The irradiation excites pi phase kinks in the junctions, which stimulate the cavity resonance when the bias voltage is tuned. A large amount of dc energy is then pumped into the Josephson plasma oscillation, and the incident wave gets amplified. From the profound current step in IV characteristics induced at the cavity resonance, the system can also be used for detection of the THz wave.